add W3CBaggagePropagatorTests

tracer/test/Datadog.Trace.Tests/Propagators/W3CBaggagePropagatorTests.cs

@@ -0,0 +1,250 @@
+// <copyright file="W3CBaggagePropagatorTests.cs" company="Datadog">
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
+// </copyright>
+
+using System;
+using Datadog.Trace.Headers;
+using Datadog.Trace.Propagators;
+using FluentAssertions;
+using Moq;
+using Xunit;
+
+namespace Datadog.Trace.Tests.Propagators;
+
+public class W3CBaggagePropagatorTests
+{
+    private static readonly SpanContextPropagator BaggagePropagator;
+
+    static W3CBaggagePropagatorTests()
+    {
+        BaggagePropagator = SpanContextPropagatorFactory.GetSpanContextPropagator(
+            [ContextPropagationHeaderStyle.W3CBaggage],
+            [ContextPropagationHeaderStyle.W3CBaggage],
+            propagationExtractFirst: false);
+    }
+
+    public static TheoryData<string, (string Key, string Value)[]> InjectBaggageData
+        => new()
+        {
+            // expectedHeader, inputPairs
+            { string.Empty, [] },
+            { string.Empty, [("key1", null)] },
+            { string.Empty, [("key1", string.Empty)] },
+            { "key1=value1,key2=value2", [("key1", "value1"), ("key2", "value2")] },
+            { "key1=value1=valid", [("key1", "value1=valid")] },
+            { "%20key1%20=%20value1%20", [(" key1 ", " value1 ")] },
+            { "name=Jos%C3%A9", [("name", "José")] },
+            { "key%F0%9F%90%B6=value%F0%9F%98%BA", [("key🐶", "value😺")] },
+        };
+
+    public static TheoryData<string, (string Key, string Value)[]> ExtractBaggageData
+        => new()
+        {
+            // inputHeader, expectedPairs
+            { null, null },
+            { string.Empty, null },
+            { " ", null },
+            { "invalid", null },
+            { "invalid=", null },
+            { "=invalid", null },
+            { "=", null },
+            { "key1=value1,key2=value2", [("key1", "value1"), ("key2", "value2")] },
+            { "key1=value1,invalid", [("key1", "value1")] },
+            { "key1=value1=valid", [("key1", "value1=valid")] },
+            { "%20key1%20=%20value1%20", [(" key1 ", " value1 ")] },
+            { "name=Jos%C3%A9", [("name", "José")] },
+            { "key%F0%9F%90%B6=value%F0%9F%98%BA", [("key🐶", "value😺")] },
+            { "key1 = value1, key2 = value2 ", [("key1", "value1"), ("key2", "value2")] },
+        };
+
+    [Theory]
+    [InlineData("abcd", new char[0], "abcd")]
+    [InlineData("abcd", new[] { 'x' }, "abcd")]
+    [InlineData("abcd", new[] { 'b', 'd' }, "a%62c%64")]
+    [InlineData("José", new char[0], "Jos%C3%A9")]
+    [InlineData("🐶", new char[0], "%F0%9F%90%B6")]
+    public void Encode(string value, char[] charsToEncode, string expected)
+    {
+        W3CBaggagePropagator.Encode(value, [..charsToEncode]).Should().Be(expected);
+    }
+
+    [Theory]
+    [InlineData("abcd", "abcd")]
+    [InlineData("a%62c%64", "abcd")]
+    [InlineData("Jos%C3%A9", "José")]
+    [InlineData("%F0%9F%90%B6", "🐶")]
+    public void Decode(string value, string expected)
+    {
+        W3CBaggagePropagator.Decode(value).Should().Be(expected);
+    }
+
+    [Theory]
+    [MemberData(nameof(InjectBaggageData))]
+    public void CreateHeader(string expectedHeader, (string Key, string Value)[] inputPairs)
+    {
+        var baggage = new Baggage();
+
+        foreach (var pair in inputPairs)
+        {
+            baggage.Set(pair.Key, pair.Value);
+        }
+
+        W3CBaggagePropagator.CreateHeader(baggage, W3CBaggagePropagator.DefaultMaximumBaggageItems, W3CBaggagePropagator.DefaultMaximumBaggageItems)
+                            .Should()
+                            .Be(expectedHeader);
+    }
+
+    [Theory]
+    [InlineData(0, "")]
+    [InlineData(1, "key1=value1")]
+    [InlineData(2, "key1=value1,key2=value2")]
+    public void CreateHeader_MaxItems(int maxBaggageItems, string expected)
+    {
+        var baggage = new Baggage();
+        baggage.Set("key1", "value1");
+        baggage.Set("key2", "value2");
+
+        W3CBaggagePropagator.CreateHeader(baggage, maxBaggageItems, W3CBaggagePropagator.DefaultMaximumBaggageItems)
+                            .Should()
+                            .Be(expected);
+    }
+
+    [Theory]
+    [InlineData("Jose", 20, "name=Jose")]
+    [InlineData("Jose", 21, "name=Jose,key2=value2")]
+    [InlineData("José", 25, "name=Jos%C3%A9")]
+    [InlineData("José", 26, "name=Jos%C3%A9,key2=value2")]
+    public void CreateHeader_MaxLength(string value, int maxBaggageLength, string expected)
+    {
+        var baggage = new Baggage();
+        baggage.Set("name", value);
+        baggage.Set("key2", "value2");
+
+        W3CBaggagePropagator.CreateHeader(baggage, W3CBaggagePropagator.DefaultMaximumBaggageItems, maxBaggageLength)
+                            .Should()
+                            .Be(expected);
+    }
+
+    [Theory]
+    [MemberData(nameof(ExtractBaggageData))]
+    public void ExtractHeader(string inputHeader, (string Key, string Value)[] expectedPairs)
+    {
+        var baggage = W3CBaggagePropagator.ParseHeader(inputHeader);
+
+        if (expectedPairs is null || expectedPairs.Length == 0)
+        {
+            baggage.Should().BeNull();
+            return;
+        }
+
+        expectedPairs.Length.Should().Be(baggage!.Items?.Count);
+
+        foreach (var pair in expectedPairs)
+        {
+            baggage.Get(pair.Key).Should().Be(pair.Value);
+        }
+    }
+
+    [Fact]
+    public void Inject_IHeadersCollection()
+    {
+        var headers = new Mock<IHeadersCollection>();
+        var context = CreatePropagationContext();
+
+        BaggagePropagator.Inject(context, headers.Object);
+
+        headers.Verify(h => h.Set("baggage", "key1=value1,key2=value2"), Times.Once());
+        headers.VerifyNoOtherCalls();
+    }
+
+    [Fact]
+    public void Inject_CarrierAndDelegate()
+    {
+        // using IHeadersCollection for convenience, but carrier could be any type
+        var headers = new Mock<IHeadersCollection>();
+        var context = CreatePropagationContext();
+
+        BaggagePropagator.Inject(context, headers.Object, (carrier, name, value) => carrier.Set(name, value));
+
+        headers.Verify(h => h.Set("baggage", "key1=value1,key2=value2"), Times.Once());
+        headers.VerifyNoOtherCalls();
+    }
+
+    [Fact]
+    public void Extract_IHeadersCollection()
+    {
+        var headers = new Mock<IHeadersCollection>(MockBehavior.Strict);
+
+        headers.Setup(h => h.GetValues("baggage"))
+               .Returns(["key1=value1,key2=value2"]);
+
+        var result = BaggagePropagator.Extract(headers.Object);
+        headers.Verify(h => h.GetValues("baggage"), Times.Once());
+
+        var baggage = result.Baggage!;
+        baggage.Should().NotBeNull();
+        baggage.Get("key1").Should().Be("value1");
+        baggage.Get("key2").Should().Be("value2");
+
+        result.SpanContext.Should().BeNull();
+    }
+
+    [Fact]
+    public void Extract_CarrierAndDelegate()
+    {
+        // using IHeadersCollection for convenience, but carrier could be any type
+        var headers = new Mock<IHeadersCollection>(MockBehavior.Strict);
+
+        headers.Setup(h => h.GetValues("baggage"))
+               .Returns(["key1=value1,key2=value2"]);
+
+        var result = BaggagePropagator.Extract(headers.Object, (carrier, name) => carrier.GetValues(name));
+        headers.Verify(h => h.GetValues("baggage"), Times.Once());
+
+        var baggage = result.Baggage!;
+        baggage.Should().NotBeNull();
+        baggage.Get("key1").Should().Be("value1");
+        baggage.Get("key2").Should().Be("value2");
+
+        result.SpanContext.Should().BeNull();
+    }
+
+    [Theory]
+    [InlineData("foo")]
+    [InlineData("key=")]
+    [InlineData("=value")]
+    [InlineData("=")]
+    [InlineData("")]
+    [InlineData("  ")]
+    [InlineData(null)]
+    public void Extract_InvalidFormat(string header)
+    {
+        var headers = new Mock<IHeadersCollection>(MockBehavior.Strict);
+
+        headers.Setup(h => h.GetValues("baggage"))
+               .Returns([header]);
+
+        var context = BaggagePropagator.Extract(headers.Object);
+
+        headers.Verify(h => h.GetValues("baggage"), Times.Once());
+        context.Baggage.Should().BeNull();
+        context.SpanContext.Should().BeNull();
+    }
+
+    private static PropagationContext CreatePropagationContext()
+    {
+        var spanContext = new SpanContext(
+            new TraceId(0x0123456789abcdef, 0x1122334455667788),
+            987654321,
+            SamplingPriorityValues.UserKeep,
+            serviceName: null,
+            origin: null);
+
+        var baggage = new Baggage();
+        baggage.Set("key1", "value1");
+        baggage.Set("key2", "value2");
+
+        return new PropagationContext(spanContext, baggage);
+    }
+}